@article { ISI:000287281900003, title = {Esterification of levulinic acid to n-butyl levulinate over heteropolyacid supported on acid-treated clay}, journal = {Journal of Natural Gas Chemistry}, volume = {20}, number = {1}, year = {2011}, month = {JAN}, pages = {18-24}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Levulinic acid has been identified as a promising green, biomass-derived platform chemical. n-Butyl levulinate is used as an important intermediate having diverse applications. The present work focuses on the synthesis of n-butyl levulinate by esterification of levulinic acid with n-butanol using heteropolyacid (HPA) supported on acid-treated clay montmorillonite (K10). 20\% (w/w) dodecatungestophosphoric acid (DTPA) supported on K10 was found to be the most efficient catalyst with 97\% levulinic acid conversion and 100\% selectivity towards n-butyl levulinate. Effects of various process parameters were studied to examine the efficacy of 20\% (w/w) DTPA/K10 for optimization of the activity.

}, keywords = {dodectungestophosphoric acid, K10, levulinic acid, n-butanol, n-Butyl levulinate}, issn = {1003-9953}, doi = {10.1016/S1003-9953(10)60147-8}, author = {Dharne, S. and Bokade, Vijay V.} } @article { ISI:000328527000041, title = {Esterification of levulinic acid to ethyl levulinate over bimodal micro-mesoporous H/BEA zeolite derivatives}, journal = {Catalysis Communications}, volume = {43}, year = {2014}, month = {JAN}, pages = {188-191}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A series of bimodal micro-mesoporous H/BEA zeolite derivatives were prepared by the post-synthesis modification of H/BEA zeolite by NaOH (0.05 M-1.2 M) treatment Samples were characterized by powder XRD, low temperature nitrogen adsorption/desorption, temperature programmed desorption of ammonia and ICP. The mesopore formation was found to play a crucial role in liquid phase esterification of levulinic acid with ethanol. The enhanced catalytic activity of a bimodal micro-mesoporous H/BEA zeolite derivative (H/BEA(0.10)) prepared by treatment with 0.1M NaOH can be mainly attributed to the high mesoporosity coupled with better preserved crystallinity and acidic properties. (C) 2013 Elsevier B.V. All rights reserved.

}, keywords = {Esterification, ethyl levulinate, H/BEA zeolite, Mesoporosity, Post-synthesis modification}, issn = {1566-7367}, doi = {10.1016/j.catcom.2013.10.006}, author = {Patil, C. R. and Niphadkar, P. S. and Bokade, Vijay V. and Joshi, P. N.} } @article { ISI:000341764500007, title = {Esterification of renewable levulinic acid to ethyl levulinate biodiesel catalyzed by highly active and reusable desilicated H-ZSM-5}, journal = {Journal of Chemical Technology and Biotechnology}, volume = {89}, number = {10}, year = {2014}, month = {OCT}, pages = {1507-1515}, publisher = {WILEY-BLACKWELL}, type = {Article}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

BACKGROUNDIn the near future, fossil fuel will have limitations in terms of availability and also great concerns over its environmental impact. New routes and related technologies based on renewable feedstocks can overcome most of these problems associated with fossil fuel. Among current biodiesel sources, ethyl levulinate (EL) biodiesel obtained from catalytic esterification of renewable levulinic acid (LA) with ethanol has received a great deal of attention. The use of desilicated H-ZSM-5 (DH-ZSM-5) as heterogeneous acid catalyst for EL biodiesel production in a closed system (under autogeneous pressure) was studied. RESULTSThe effect of reaction parameters such as ethanol to LA molar ratio (4:1 to 10:1), catalyst to LA ratio (0.10-0.25), speed of agitation (100-400rpm), particle size (53-355 mu m), reaction temperature (363-403K) and reaction time (7h) was investigated to maximize LA conversion. CONCLUSIONLevulinic acid conversion reached 95\% over DH-ZSM-5 and the catalyst was reusable for up to six cycles. This LA conversion and the catalyst reusability values are higher than others reported in the literature. A pseudo-homogeneous (P-H) kinetic model indicated that reaction rate constants increased with increasing molar ratio, catalyst to LA ratio and reaction temperature. The activation energy decreased from 73.14 to 21.08 kJ mol(-1) when increasing the catalyst to LA ratio from 0.10 to 0.25, which implies a kinetically controlled reaction. (c) 2013 Society of Chemical Industry

}, keywords = {desilicated H-ZSM-5, Esterification, ethyl levulinate, levulinic acid}, issn = {0268-2575}, doi = {10.1002/jctb.4228}, author = {Nandiwale, Kakasaheb Y. and Niphadkar, Prashant S. and Deshpande, Shilpa S. and Bokade, Vijay V.} } @article { ISI:000355231200019, title = {Environmentally benign catalytic process for esterification of renewable levulinic acid to various alkyl levulinates biodiesel}, journal = {Environmental Progress \& Sustainable Energy}, volume = {34}, number = {3}, year = {2015}, month = {SEP}, pages = {795-801}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

This study explores, the use of modified zeolite (Micro/Meso-HZ-5) obtained by desilication post-treatment as heterogeneous catalyst for esterification of biomass derived renewable levulinic acid (LA) with different alkyl alcohols such as methanol, ethanol, n-butanol, and n-octanol aiming to produce corresponding alkyl levulinate. This method of production of alkyl levulinates would be sustainable process, as it can be used as novel miscible diesel biofuels preventing global warming by decreasing atmospheric CO2. The LA conversion obtained over Micro/Meso-HZ-5 was higher than H-ZSM-5, which is due to the combined effect of increase in Bronsted acid sites, total acidity, and other properties such as BET surface area and the generation of mesoporosity. The maximum LA conversion of 91, 95, 96, and 98\% with 100\% selectivity toward alkyl levulinate was obtained, when LA was being esterified over Micro/Meso-HZ-5 with methanol, ethanol, n-butanol, and n-octanol, respectively, at optimal process parameters. Micro/Meso-HZ-5 catalyst was found to be reusable for six cycles. Furthermore, pseudo homogeneous (P-H) kinetic model of the esterification of LA with the studied four alcohols were established with R-2\>0.99, using the experimental data. A P-H kinetic model implies that, the esterification reaction follows second order reversible kinetics. (c) 2014 American Institute of Chemical Engineers Environ Prog, 34: 795-801, 2015

}, keywords = {biofuels, Esterification, kinetic model, levulinic acid, meso-HZ-5, micro}, issn = {1944-7442}, doi = {10.1002/ep.12042}, author = {Nandiwale, Kakasaheb Y. and Bokade, Vijay V.} } @article { ISI:000348924600005, title = {Esterification of renewable levulinic acid to n-butyl levulinate over modified H-ZSM-5}, journal = {Chemical Engineering \& Technology}, volume = {38}, number = {2}, year = {2015}, month = {FEB}, pages = {246-252}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

The synthesis of n-butyl levulinate, one of the most important biodiesel additives, by catalytic esterification of biomass-derived levulinic acid (LA) with n-butanol over modified H-ZSM-5 (micro/meso-HZ-5) in a closed-batch system is reported for the first time. The optimization of the reaction conditions such as the reactant molar ratio, the catalyst loading, the reaction time and the temperature was performed in view to maximize the yield of n-butyl levulinate. Micro/meso-HZ-5 was found to be the most efficient catalyst, with 98\% yield of n-butyl levulinate and a reusability for six cycles, which is higher than reported in the literature. A possible catalytic mechanism for the esterification reaction is also proposed. A second-order pseudo-homogeneous model with R-2 \> 0.97 confirmed that the esterification reaction is performed in the kinetic regime due to the high activation energy of 23.84 kJ mol(-1).

}, keywords = {Esterification, kinetic model, levulinic acid, Micro/meso-HZ-5, n-Butyl levulinate}, issn = {0930-7516}, doi = {10.1002/ceat.201400326}, author = {Nandiwale, Kakasaheb Y. and Bokade, Vijay V.} } @article {46147, title = {Epoxidation of karanja (Millettia pinnata) oil methyl esters in the presence of hydrogen peroxide over a simple niobium-containing catalyst}, journal = {Catalysts}, volume = {9}, year = {2019}, month = {APR}, pages = {344}, type = {Article}, abstract = {

The synthesis, characterization and catalytic performance of a conceptually simple, novel NbOx-SiO2 catalyst are here described. The niobium(V)-silica catalyst was prepared starting from cheap and viable reactants, by alkaline deposition of NH4Nb(C2O4)(2)H2O in the presence of fructose as a stabilizer and subsequent calcination. The NbOx-SiO2 solid (0.95 Nb wt.\%) was tested in the liquid-phase epoxidation with aqueous hydrogen peroxide of methyl oleate, as a model substrate. It was then tested in the epoxidation of a mixture of methyl esters (FAMEs) obtained by transesterification with methanol and purification of karanja oil, extracted from the autochthonous Indian variety of Millettia pinnata tree. The catalyst showed a promising performance in terms of methyl oleate conversion (up to 75\%) and selectivity to epoxide (up to 82\%). It was then tested on the FAME mixture from karanja oil, where interesting conversion values were attained (up to 70\%), although with lower selectivities and yields to the mixture of desired epoxidized FAMEs. The solid withstood four catalytic cycles overall, during which a non-negligible surface reorganization of the Nb(V) sites was observed. However, this restructuring did not negatively affect the performance of the catalysts in terms of conversion or selectivity.

}, keywords = {epoxidation, fatty acid methyl esters, heterogeneous catalysis, Hydrogen peroxide, karanja oil, mesoporous silica catalyst, Millettia pinnata, niobium catalysts}, issn = {2073-4344}, doi = {10.3390/catal9040344}, author = {Scotti, Nicola and Ravasio, Nicoletta and Evangelisti, Claudio and Psaro, Rinaldo and Penso, Michele and Niphadkar, Prashant S. and Bokade, Vijay V. and Guidotti, Matteo} } @article {47071, title = {Effect of rice husk particle size on ZSM-5 physico-chemical properties for selective formation of 1,3,5-trimethyl-2-benzylbenzene (Pharmaceutical Intermediate)}, journal = {ChemistrySelect}, volume = {6}, year = {2021}, month = {FEB }, pages = {1255-1262}, type = {Article}, abstract = {

Rice husk, rich in silica and abundantly available as waste, is presently destroyed by burning, which creates environmental issues. Thus, it will be advantageous if this rice husk waste can be used for preparation of valuable products. One of the application is its use as silica source in the synthesis of zeolites like ZSM-5, which are silico-aluminates. Rice husk waste is available in wide range of particle sizes in agricultural farms. There is no study available in open literature on use of these wide particle ranges for its direct application. This paper is an attempt to use wide particle size rice husk, its effect on ZSM-5 synthesis and its physico-chemical properties. Further these prepared ZSM-5 catalyst was evaluated for benzylation of mesitylene reaction. The study found that, rice husk of 600 mu m particle size is optimum as far as ZSM-5 synthesis, its physicochemical properties and further its application in mesitylene benzylation reaction.

}, keywords = {Mesitylene, Particle size, rice husk, Silica Source, ZSM-5}, issn = {2365-6549}, doi = {10.1002/slct.202004802}, author = {Ghuge, Gorakh and Niphadkar, Prashant and Rathod, Simmy and Bokade, Vijay V.} } @article {48702, title = {Equilibrium adsorption of nitrogen, oxygen, and argon on silver-exchanged hierarchical ETS-10}, journal = {Journal of Chemical and Engineering Data}, volume = {68}, year = {2023}, month = {JUL}, pages = {2159-2172}, type = {Article}, abstract = {

Silver-exchanged hierarchical ETS-10(Ag-H-ETS-10) was synthesizedusing Ag+ exchange with hierarchical Engelhard titanosilicate(H-ETS-10) using silver nitrate solution. The physical propertiesof the adsorbent were analyzed using X-ray diffraction (XRD), BETsurface area, nitrogen adsorption-desorption, pore volume,energy dispersive spectroscopy (EDS), and high resolution-transmissionelectron microscopy (HR-TEM). N-2 physisorption data confirmedthat a micro-mesoporous (bimodal) structure was created in the Ag-H-ETS-10.The equilibrium adsorbent data of pure gases N-2, O-2, and Ar were investigated in the temperature range from 288to 318 K up to 10 bar. The equilibrium adsorption capacity of Ag-H-ETS-10was found to be 1.12 mmol g(-1) for N-2,0.87 mmol g(-1) for O-2, and 1.09 mmol g(-1) for Ar at 298 K and \& SIM;10 bar. \& SIM;20\% higheradsorption capacity was found for N-2 and Ar in Ag-H-ETS-10compared to Ag-ETS-10. The higher sorption capacity was attributedto the formation of a bimodal structure and \& pi;-complexation interactionby the Ag cation, which allows a multilayer of N-2 and Armolecules. The Sips isotherm model was well fitted for the Ag-H-ETS-10experimental data among Langmuir, Freundlich, Toth, and Temkin models.The measured equilibrium adsorption data for Ag-H-ETS-10 can be usefulfor the O-2 purification process.

}, issn = {0021-9568}, doi = {10.1021/acs.jced.3c00124}, author = {Shrotri, Aadesh R. and Niphadkar, Prashant S. and Bokade, Vijay V. and Nandanwar, Sachin U.} } @article {48905, title = {Effect of CTMABr/SiO2 molar ratio in synthesis of micro-mesoporous ZSM-5 composite and its application in 5-EMF (biofuel additive) formation}, journal = {Environmental Progress and Sustainable Energy }, volume = {43}, year = {2024}, month = {JAN}, type = {Article}, abstract = {

Synthesis of micro-mesoporous zeolite composite with optimum micro and mesoporosity is an emerging research area due to its wide applications, especially in bulk chemical or biomass transformations. It offers advantages in preserving zeolite crystallinity, creating mesoporosity and converting bulky molecules into valuable products. This work presents the process of preparing bimodal micro-mesoporous ZSM-5 using dual templates (CTMABr and TPABr). XRD, N2 adsorption-desorption, SEM, TEM, Si-29, and Al-27 NMR were used to analyze the two-dimensional micro-mesoporous ZSM-5. One-step synthesis of bimodal micro-mesoporous ZSM-5 features dual micro/mesoporosity by a marginal decrease in the crystallinity (71\%). Micro-mesoporous ZSM-5 composite was found to be dependent on the optimum CTMABr/SiO2 molar ratio of 0.04 to 0.06. The micro-mesoporous ZSM-5 zeolite composite was evaluated for cascade synthesis of 5-EMF (methoxymethyl furfural- biofuel additive) from fructose and exhibited a five fold increase in 5-EMF yield to 24.2\% as compared with parent ZSM-5 (4.6\%).

}, keywords = {fructose, methoxymethyl furfural-biofuel additive, micro-meso composite, ZSM-5}, issn = {1944-7442}, doi = {10.1002/ep.14258}, author = {Manal, Prajakta N. and Niphadkar, Prashant S. and Nandanwar, Sachin U. and Bokade, Vijay V.} }